Abstract
With increasing need for energy efficient vapor-compression cycles (VCCs), researchers have investigated different aspects of such systems to increase performance. The goal of this research is to experimentally investigate the design and control of a turbomachine expander to recover work and control the VCC. An R-410A split-system heat pump experimental setup has been utilized to compare the performance and control capabilities of a variable nozzle and a fixed nozzle with phase separation combined with evaporator bypass flow metering. A theoretical analysis on the benefit of the expander in heat pumps motivated heat pump operation in cooling mode. The variable nozzle experiments yielded a significant decrease in expander isentropic efficiency, and the evaporator bypass control led to an increase in system coefficient of performance (COP) of 2.3% with an expander overall isentropic efficiency of 18.8%. Compressor suction superheat control was achieved with the evaporator bypass over a range of ambient conditions.
Keywords
Turbomachine expander, Expander control, Evaporator bypass, Phase separation, Variable nozzle
Date of this Version
2020
Recommended Citation
Barta, Riley; Ziviani, Davide; and Groll, Eckhard A., "Experimental Analyses of Different Control Strategies of an R-410A Split-System Heat Pump by Employing a Turbomachinery Expansion Recovery Device" (2020). School of Mechanical Engineering Faculty Publications. Paper 67.
https://docs.lib.purdue.edu/mepubs/67
Comments
This is the author-accepted manuscript of Barta, RB; Ziviani, D; Groll, EA. (2020) "Experimental analyses of different control strategies of an R-410A split-system heat pump by employing a turbomachinery expansion recovery device." International Journal of Refrigeration 112: 189-200. Published by Elsevier, it's made available here CC-BY-NC-ND, and the version of record is available at DOI: 10.1016/j.ijrefrig.2019.12.027.